Office



(No Mode1.)-

- W. M. DUTY.-

GUARD-GATE POR SWING BRIDGES.

Patented- Vro " .UNITED STATES PATENT OFFICE.

WILLIAM -M. DOTY, OF CHICAGO, ILLIINOIS, ASSIGNOR OF ONE-HALF TO A. `MONIGOMERY WARD, OF SAME PLACE.

GUARD-GATE FOR SWING-BRIDGES.

SPECIFICATION forming part of Letters Patent No. 297,920, dated April 29, 1884. Application filed December 26, 1883. (No model.)

To all whom t may concern: Be it known that I, WILLIAM M. DoTY, of

Chicago, county of Cook, and State of Illinois,

have invented certain new and useful Improvements in Guard Gates for Swing- Bridges, ofwhich the following is a full, clear, and exact description, that will enable others to make and use the same, reference beinghad to the accompanying drawings, forming a part of this specication.

This invention relates to improvements in that class of guard or safety gates which are placed on the bridge-approach, and are automatically operated bythe opening and closing of the bridge.

Figure l isa view of the approach and abutment, looking from the bridge when the same is open, embodying my improved features; Fig. 2, a side elevation of the same, showing the bridge closed; Fig. 3, a modification.

Referring to the drawings, A A represent the two double gates so constructed and ar- -ranged as to close both the driveway B and the foot-passages B B2 on each side of the bridge. The bifurcated posts B3 B* are placed on the approach in line with each side of the bridge, as shown in Fig. l of the drawings. The two gate-bars C O are pivoted between these bifurcated or double posts, and are adapted to assume either a vertical or a horizontal position. The outer ends, a c', are a continuation of the gate-bars, and serve to close the foot passage-way at the same time that the driveway `is closed. When the bridge is closed, the ends a a" shut in between the supporting posts or uprights B"i Bi, as shown in Fig. 2 and indicated by dotted lines in Fig. l. The series of pickets a2 are pivoted to the gate-bars, and are self-adjusting by the force of gravity. The dotted lines in Fig. l indicate the position of the gate or gates when the bridge is closed for traffic. Underneath the bridge-approach, and in line with the gates and supporting-posts, are located the conipanion transverse levers 02.03, the outer ends of which are pivoted at a to the projecting end ofthe transverse timber G4. These levers are made very wide near the inner ends, the widened part a4 extending downward from the upper line, and are provided with a double struction and this arrangement the Ibridge may be swung either way, the two levers moving simultaneously. At a point near the longitudinal center. of the levers C2 Ca are attached the lower ends ofthe arms 5263, while the upper ends are secured to the projecting lugs b4 on the gate-bars just inside of the supportingposts, as shown in Fig. l. By means of this connection the gates are raised and lowered by a corresponding movement of the levers C2 C3. Underneath the end and transverse center of the bridge, and projecting downward therefrom. is placed the angular lever D, the horizontal part of which is provided with the friction-roller d, adapted to have frictional Contact with the under side of the inner beveled ends of the levers C2 O3, as shown in Fig. 2. The inner ends of the gate-bars are provided on the outer sides with the brackets d, which receive and retain said bars, so that vone will not drop below the other when changed to a horizontal position. The beveled ends of the-levers C2 C3 are of suicient weight to counterbalance the weight of the gates, so'that when the bridge is swung open the gates gradually descend from a vertical to a horizontal position, and when the bridge is closed the friction-roller d is broughtl in contact with the under side of the beveled ends of the levers Cl C3, raising the same upward, and the gates made to assume a vertical positionthrough the medium of the connectingarms b2 b3.

Fig. 3 is a modication showing arrangement of mechanism whereby the gates may be set back at any distance from the edge of the approach.

Having thus described my invention, what I claim as new, and desire to secure by Letters Patent, is

1. In a guard-gate for swing-bridges, the combination, with the gates A A', of the arms b2 b3, and the` companion levers G2 C, having the outer ends pivoted to the timber G4, while the inner ends are widened and beveled7 as A', and the posts B3 B4, whereby said gates described, whereby said gates are raised or are automatically opened and closed by the io lowered by the opening and closing` of the movement of the bridge.

bridge substantially as set forth. T x w 2. 11,1 a guardgate for swing-bridges, the W ILLIAM M' DOrlY' combination7 with :t bridge7 of the angular lel Witnesses: ver D, the friction-roller d, the companion le L. M. FREEMN, vers Cz C3, the vertical arms b b3, the gates A C. S. JONES. 

